If you find this package useful, please cite:

Sigg CD and Buhmann JM (2008). “Expectation-Maximization for Sparse and Non-Negative PCA.” In Proc. 25th International Conference on Machine Learning.

Corresponding BibTeX entry:

  @InProceedings{sigg2008expectation,
    author = {Christian D. Sigg and Joachim M. Buhmann},
    title = {Expectation-Maximization for Sparse and Non-Negative PCA},
    booktitle = {Proc. 25th International Conference on Machine
      Learning},
    year = {2008},
  }